The use of social media websites continues to increase. A recent survey shows that 85 million people currently use LinkedIn, 175 million use Twitter and 500 million use Facebook. Earlier this year, Facebook had one trillion page views in a single month. According to the Pew Research Center, the recent surge in social media use has been most pronounced among people over age 35, with 48 percent of those 36 and older using at least one social networking site.

These websites provide employers with a wealth of information about users’ personal and professional lives. With this data, however, come new questions about how employers should use social media to recruit and screen potential employees. Here are a few tips employers should bear in mind when navigating the new social media frontier.

Use Social Media to Your Advantage

The top three social media networks, LinkedIn, Twitter and Facebook, all provide unique recruiting opportunities for employers. According to a recent Jobvite survey, 89 percent of companies are either using or planning to use social media to support their recruiting efforts in 2011. Of these employers, 64 percent have used two or more social media networks and 87 percent have used LinkedIn.

LinkedIn is perhaps the most well-known professional networking site on the web. Hiring managers can post jobs, set up automatic search alerts, contact candidates directly through InMail and interact with users through LinkedIn Groups and LinkedIn Answers. LinkedIn allows employers to target both active and passive candidates. The website is particularly useful for companies recruiting overseas, as approximately half its members reside outside the United States.

Twitter helps employers interact with users through the use of short personal messages. With its 140-character messaging limit, Twitter allows employers to notify followers of job vacancies and employment opportunities. Additionally, 63 percent of Twitter users provide profi le data, which includes location, biography and website information. With 95 million tweets written per day, Twitter offers employers an easy and effective way to keep in touch with candidates.

Finally, with the largest cyber audience of any social media network, Facebook is a gold mine of user information. Although traditionally thought of as a personal networking website, Facebook can help employers establish a sustained presence on the web. Recruiters can post messages on the company’s fan page, send direct messages to “friends” or place a Facebook Ad. The average user has 130 “friends,” and on an average day 50 percent of all active users log onto Facebook. Given the extraordinary reach of this network, more employers are exploring ways to use Facebook in their outreach efforts.

Those employers who already use social media for recruiting report success, with 58 percent using a social network to hire a qualifi ed candidate in the last year. Of those, 95 percent used LinkedIn, 24 percent used Facebook and 16 percent used Twitter. Investment in social media recruiting is also increasing, with 54 percent of respondents reporting a boost in social media investment for 2011, a higher rate of increase than that reported for any other recruiting method.

Understanding the Legal Landscape

With this increased use and investment come new questions about what types of social media practices violate the law. Although the law is still developing in this area, there are a few basic principles employers should keep in mind.

First, employers should be careful not to use as part of their hiring criteria any information that they would not normally consider during the hiring process. Social media websites often contain information about a candidate’s race, religion, age, national origin, sexual orientation, disabilities, genetic information, marital status and political affi liation. Many of these characteristics are protected by federal, state or local law. The mere mention of a nonobvious protected characteristic during the hiring process could be suffi cient to entangle the employer in costly litigation, regardless of whether the employer actually took the characteristic into consideration in making its hiring decision.

Employers must also be familiar with the “offduty” laws in their states. At least 28 states currently prohibit employers from taking an adverse employment action based on an employee’s lawful off-duty conduct. Many of these laws apply to potential employees as well. For example, in Minnesota, it is unlawful for an employer to require a prospective employee to refrain from using lawful consumable products, such as food, alcohol and tobacco, during nonworking hours. Minn. Stat. Ann. § 181.938. New York goes a step further by protecting all lawful recreational activities, including political activities, during nonworking hours. N.Y. Lab. Law § 2001-d. It is critical for employers to understand these laws and refrain from considering any protected activities in their hiring decisions.

Finally, an employer who makes an employment decision based on information randomly obtained on Google or social media networks could face a disparate-impact claim from applicants if it does not have a standard search policy in place. To overcome such a claim, the employer must prove that it treats all applicants in a similar manner, a showing that may be diffi cult to make if the employer does not have or follow a written search policy.

Limit Liability Through Use of Third-Party Providers

Fortunately, third-party Internet search providers are lining up to assist employers. For a fee, companies such as Social Intelligence Corp. and Tandem Select will conduct a comprehensive Internet search and compile a report about a potential employee’s cyber footprint. These reports carefully omit any potentially discriminatory information. Employers can choose from a variety of predetermined Internet search criteria such as the presence of explicit photos, racist remarks or illegal activity. They can also request searches for positive attributes such as volunteer work, industry infl uence and professional accomplishments. These controlled searches provide employers with a way to capture relevant job-related information while avoiding some of the legal pitfalls of social media recruiting.